Testing apparatus



Patented June 11, 1946 TESTING APPARATUS William Newton, Notre DaniedeGrace, Quebec, Canada, assignor to Western Electric Company,4Incorporated, New York, N .'Y., a corporation of New York ApplicationFebruary .6, 1943, Serial No. 4374,95!)

6 Claims.

This invention relates to testing apparatus and more particularly toapparatus for testing coils being wound simultaneously on a plurality ofwinding mechanisms.

It is an object of the present invention to reduce the amount` ofapparatus necessary for testing a plurality of coils being'woundsimultaneously.

In accordance with one embodiment of the invention, each of the winding'mechanisms has a search coil and a balancing coil individual to it forconstituting two arms of a Wheatstone bridge including two arms commonto all of the winding mechanisms. The search coils are movedcontemporaneously with the distribution of wire on the coils lbeingformed and are connected sequentially to the common arms of the bridgecircuitwhereby the occurrence of a fault in the coil being wound willimbalance the bridge circuit, which will" complete circuits to stop thewinding mechanism in which the defective coil is being wound and toindicate such condition.

A. better understanding of the invention may be had byV reference to thefollowing detailed descriptionr of one embodiment thereof whenconsidered in conjunction with the accompanying drawing, wherein thesingle figure includes a circuit diagram of the electrical connectionsand apparatus'and a schematic of the winding apparatus with which thecircuit cooperates.

In the drawing, there areV shown four winding mechanisms, designatedgenerally by the numeralsA I,` 2, 3 and 4. The winding mechanisms areall of exactly the same construction and only one of them will bedescribed in detail, that is, the winding mechanism I. In the windingmechanism I, there is provided a motor 5 adapted to be connected to a110 volt alternating current source at 6 through a manually operableswitch 1 and a normally open solenoid actuated switch 8. The motor 5,through suitable gearing, as indicated at 9, drives a chuck I and adistributor shaft II. The chuck Il! is adapted to hold and rotate aspool I2 composed of a pair of heads I3-I3 and a core I4 on which astrand of insulated wire I is to be wound. The strand of wire I5y may bewithdrawn from a supply spool I6, passing over guide sheaves I1, I8 andI9. The guide sheave I9 is mounted upon a distributor member 2D, adaptedto be moved back and forth on the distributor shaft I I by the usualdou-ble thread, as indicated diagrammatically in the drawing. Inaddition to supporting the guide sheaveIS, the distributor'member 20also carries a'fsarch'coil 2|, which will thus be carried lback 2' andforth with the distributor andwhich serves as a detector, in conjunctionwith the circuit with which it is connected, for any aws in theinsulation of theV wire beingwrapped on the core I4, which will causeashort circuit in the winding. The structure described hereinbefore isduplicated in each of the winding mechanisms I 2, 3 and 4 andthe'rwinding mechanisms 2, Sfand 4 havesearchcoils-22,- 23 and 24associated with them which are Vsimilar to'` the search coil 2I in thewinding'mechanism I;- Inyadditionto the searchv coilsv 2|, 22,23`-and24, each ofthe winding mechanisms have individual to it astandard coil 25, 26, Zi-and'Z-B; respectively, equipped with cores 2Q,-BD', 3i and 32; similar to the core I4 in its associated windingmechanism. Thestandard coil and the Search coil at each of the windingmechanismsv are periodically associated withVv a pair of resista-nceAarms 33y and 34 and when one searchV coil and its associatedV standardcoil are connected to the resistance'armsV 33 and 34, they will completea Wheatstone bridge circuit to which poweris supplied from a 2,000 cycleoscillator supply 35;

From the foregoing, it willbe-apparent that the resistance arms` 33'and34 are common toV all of the winding machines and, whenn connectedf tothesearch'coil and standard coil at aY Winding machine, will constitutea bridge circuit'. The bridge circuitV has connected across it ahighlysensitivev meter type relay 36gin'series with a rectier '31, which willYpermit the currentto flow acrossthe coil of the meter type relay only inone direction and when the bridge circuit, including the resistancearmsv 33 and 34 isunbalanced,v the currentwill vflow in said directionto energize the coil of theA meter type relay and cause it to close itscontacts 38. The contacts- 38A are periodically connectedthroughthe-operation of a stepper switch, Adesignatedv generally by the numeral39, sequentially to the *windings of relays 40, 4I, 42 and 43. Thestepper switch 39 is provided with four 'brushes i5, 46 and il and maybe set in operation in any suitable ymanner to step its brushes intoNassociation with banks of contacts individual thereto step by step whilethe apparatus is in operation. The brushes 45 and 41 are connectedt'oone sidev of the coil of the meter typerelay and to ground at 48.When the brushes 46 and 4'I are moved step by'step into contact with thecontacts of their associated banks, ytlfiey'fwill iirst serve to connectthe standard coil 25l and searchcoil 2i to the opposite ends oftheresistance arms 33v and 34 whilethe brushes are in the position shown.

s soon as the brushes 46 and 41 step out ofV circuit associated witheach of the winding machines I, 2, 3 and 4, utilizing the commonresistance arms 33 and 34 and the paired searchYV and standard coils ateach winding machine. So long as no iiaws are detected in the windingsapplied to the cores I4, at the various winding mechanisms, the bridgecircuits thus set up will remain in balance, but when a short circuitedturn is detected, the electrical characteristics of the various windingmechanisms is completed, as

pointed out hereinbefore, through the normally open solenoid operatedswitch 8 and power is supplied to energize a solenoid 55, a solenoid 56,a solenoid 51 and a solenoid 58, after closing the switch associatedwith the motor 5 in the winding mechanisms I, 2, 3 and 4, respectively,when the relays 40, 4I, 42 and 43 associated with those windingmechanisms are deenergized. At the initiation of the operation of thevarious winding mechanisms, the test circuits therefor may be renderedoperative by closing switches 59, 60, 6I and 62 at the respectivewinding machines to energize relays 63, 64, 65 and 66, which will lockup through their locking contacts and connect ground at the relays 46,4I, 42 and 43 to hold the relays 63, 64, 65 and 66 energized until theirassociated relays 40, 4I, 42 and 43 are energized.

In the normal operation of the apparatus, when no faults are found inthe coils being wound, a

' the search coil associated with the mechanism in j green signal lamp61 at each winding mechanism v will have battery connected to it througha' con- 'tact of its associated relay 63, 64, 65 or 66 to indicate thatthe operation of the apparatus is proceeding in a satisfactory manner.However,

as soon as a fault occurs in any one of the wind;

ing mechanisms, a red lamp 68 associated therewith will have currentsupplied to it from grounded battery at the make contact of itsassociated relay 40, 4I, 42 or 43.

Anytime the meter type relay 36 is energized to close the contacts 38,there will be a tendency for the contacts to remain locked and,accordingly, the brush is provided for supplying a releasing or kickback current to the core of the meter type relay 36 through the second,fourth,

sixth and eighth contacts of its associated contact bank.

A better understanding of the apparatus may be had by reference to thefollowing brief description of the mode of operation thereof. Operatorsat the various winding mechanisms I, 2, 3

and 4 may initiate operation of their respective winding mechanisms byclosing the switches 1 associated therewith and the switches 59, 60, 6Iand 62, selectively. When any one of the switches 59 to 62 and itsassociated switch 1 are closed,

Vspond to -relay and due to the operation of the relay 63, 64,

65 or 66, its associated relay 40, 4I, 42 or 43 will supply ground atits break contact to lock the relay 63,-64, 65 or 66 energized.

Prior to the initiation of the operation of a winding machine, it isnecessary to connect the 2,000 cycle oscillating supply to the bridgecircuit including the resistance arms 33 and 34 and to initiate the stepby step operation of the brushes 44 to 41, inclusive. The tests on thecoils being wound will take place sequentially if the winding machinesare operated and the brush 44 will prepare a circuit through itsassociated contacts to the relays 40, 4I, 42 and 43 in sequence.' If nofaults in the coils being wound are found by the search coils 2I, 22, 23and 24, the Winding mechanisms I, 2, 3 and 4, which have been started inoperation manually by the closure. of switch 1 associated therewith andthe manually operable switches 59, 60, 6I and 62, the search coils andtheir associated standard coils 25l will be connected to the resistancearms 33 and 34 through the brushes 46 and 41, in sequence once for eachhalf rotation of the brushes 44 to'41 and lsince the standard coils 25,26, 21 and 28 correthe coil being wound inthe various windingmechanisms, the bridge will remain balanced each time the circuit to itis completed, unless there is some fault in the insulation of the coilbeing wound. When a fault occurs in one of the coils being wound, forexample, the coil in the winding mechanism I, the balance between thesearch coil 2l and the standard coil 25 will be disturbed by the changein inductance between the search coil and the coil being wound and,accordingly, the meter type relay 36 will be operated to close itscontacts 38 and will'supply ground from through the brush 44 to energizethe relayj40.

As soon as the relay 40 operates, it will break:

Itime the brush 44 engages its first contact, theA relay 40 will againbe energized unless'the unbalanced condition between the search coil 2Iand standard coil 25 is corrected. Thus, the red signal lamp 68 willflash until the balanced condition between the search coil 2I andstandard coil 25 is reestablished byremoving the defective winding atthe winding i. mechanism I. YAs soon as the defective winding atwindingmechanism I has been removed, the testing operation'may be reinitiatedby again closing the switch 59 anda new test will proceed. The relays4I, 42 and 43 will be energized if the strand of lwire beingied to thewinding mechanisms 2, 3=or 4 is defective in a manner similar to thatdescribed in connec-f. .non YWithtne winding mechanism l. andY the,

brushes 44 to 41 will prepare a circuit to the meter the contacts of themeter typerelay type relay 38 repeatedly under control of the relays 40,4I, 42 and 43 in sequence and will simultaneously, with the associationof the brush 44 with the relay 40 to 43, connect the search coils 2|,22, 23 and 24 and standard coils 25, 26, 21 and 28, respectively, intothe bridge circuit, the brush 45 serving to restore the meter type relayif necessary after it has been associated with each of the relays 40 to43.

In this manner, the resistance arms 33 and 34, to which the supply ofpower from the oscillator may be regulated by an adjustable resistancel0, are made common to the four winding machines and, therefore, it isnot necessary to duplicate all of the equipment at each windingmechanism.

What is claimed is:

l. The combination of a. coil Winding machine having means for rotatinga core and a distributor for distributing wire as it is wound on thecore with a testing apparatus for coils being Wound comprising a searchcoil mounted on the distributor in such position that its eiectiveinductance will be varied by the presence of a short circuit in a coilbeing wound, and a circuit intermittently connected to the search coiland responsive to the eective inductance thereof *to control operationof the means for rotating the core.

2. The combination of a coil winding machine having means for rotating acore and a distributor for distributing Wire as it is wound on the corewith a testing apparatus for coils being wound comprising a search. coilmounted on the distributor to encirclethe coil being wound and vary ineffective inductance upon the occurrence of a short circuit in the coilbeing wound, a test circuit responsive to the effective inductance ofthe search coil and connectible to the search coil, and means forintermittently connecting the search coil to the circuit.

3. The combination of a coil winding machine having means for rotating acore and a distributor for distributing Wire as it is wound on the corewith a testing apparatus for coils being Wound comprising a search coilvariable in effective inductance in response to the occurrence of ashort circuit in a coil being wound in the machine and mounted on thedistributor, a test circuit responsive to the eiective inductance of thesearch coil for controlling the operation of the means for rotating thecore, and means for connecting the search coil to the test circuit.

4. The combination of a coil winding machine having means for rotating acore and a distributor for distributing wire as it is wound on the corewith a testing apparatus for coils being Wound comprising a search coilmounted on the distributor and variable in effective inductance inresponse to faults in the coil being wound, a test circuit responsive tovariations in eiective inductance of the search coil and connectible tothe search coil, and means for intermittently connecting the testcircuit to the coil.

5. The combination of a plurality of coil Winding machines each having adistributor for distributing wire on a coil and means individual to eachmachine for driving it, with a search coil variable in effectiveinductance in response to a short circuit in a coil being Wound andindividual to each machine and mounted on the distributor of themachine, a standard coil individual to each machine, a pair ofresistance arms common to all of the machines, means for periodicallyassociating each search coil and standard coil with said resistance armsto complete a test circuit for a coil being wound in the machineassociated with the search and standard coil and responsive to theeiective inductance of the search coil, and means selectively controlledby the test circuit for stopping operation of any one of the drivingmeans for the coil Winding machines in which a defective coil is foundby the test circuit.

6. The combination of a plurality of coil Windim,r machines with asearch coil individual to each machine and variable in eiectiveinductance by the presence of a short circuit in a coil being wound inthe machine, a standard coil individual to each machine, a pair ofresistance arms common to all of the machines, means for periodicallyassociating each search coil and standard coil With said resistancearms, one set at a time and in sequence, to complete a test circuit fora coil being wound in the machine associated with the search andstandard coil and responsive to the eiective inductance of the searchcoil, manually operable means for initiating operation of the testcircuit and winding machine, and means under control of the test circuitfor selectively stopping operation of a Winding machine in which adefective coil is found by the test circuit.

WILLIAM NEWTON.

